The Quadrotor Drone That Carries a Warhead

The ROTEM-L made by Israel Aerospace Industries (IAI) looks like many other quadrotors buzzing around these days. It can fly for more than half an hour and is agile enough to go in and out of windows. It has a camera in the nose to give the operator a pilot's-eye view, like the drones used for FPV racing. What ROTEM has that those consumer gadgets don't is a warhead the size of two hand grenades.

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The new video below shows ROTEM going through its paces, including automated take-off and landing. It only takes a few seconds to unpack the drone from its case and make it flight-ready; it's controlled via a tablet. IAI announced earlier this month that the Israeli Defense Forces were interested in acquiring the drone.

Why send a soldier to get shot at when you can send a drone?

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ROTEM is the latest example of a "loitering munition," a combination scout drone and missile. Fixed-wing loitering munitions are increasingly common. The U.S. sent 4,000 Switchblade portable attack drones to Afghanistan, and several companies are competing in the LMAMS program that could see similar weapons becoming standard kit in 2017. (IAI is in the competition with its Green Dragon)

But a quadrotor munition is a very different type of animal. Fixed-wing drones have problems in cities. They cannot easily fly down narrow streets and alleys, and certainly not inside buildings. Trees and overhead power lines are real hazards, so these drone may have to remain hundreds of feet above the action. A quadrotor like ROTEM, by contrast, can operate at low altitudes and follow the same path a foot patrol might take. ROTEM has a sonar-type obstacle avoidance system that lets it fly through narrow spaces and navigate inside buildings. Why send a soldier to get shot at when you can send a drone?

The quadrotor's other big advantage over fixed-wing aircraft is that it designed to be recoverable. If no target is located, ROTEM can return and be reused, with the warhead disarmed by a double safety mechanism.

IAI

At 10 lbs. ROTEM is heavy for a quadrotor, though IAI claims a soldier can carry three or four plus the controller. The size is probably a reflection of the need to carry the two- pound explosive warhead. For pure reconnaissance missions, the warhead can be swapped out for a pack containing more cameras and additional batteries.

At this point, to arm a quadrotor is to follow the trend of drone evolution. Predators were flying unarmed for seven years until they got Hellfires in 2001. The U.S. Army started flying hand-launched Raven drones in 2003; the LMAMS, the armed equivalent, will come on-stream next year. The Israelis, as usual, are ahead of the drone curve here. The Pentagon could be persuaded to adopt drones only after Israeli successes. Abraham Karem, who designed the Predator, built drones in Israel before moving to the U.S.

The HAROP combat UAV

Israel is notable exporter of drones, including loitering munitions. Besides ROTEM, IAI also makes the Harop, a 300-pound drone with a 10-foot wingspan that can loiter for up to six hours before diving in with a 50-pound warhead (promo video with explosions here). According to IAI, its long endurance means the Harop can be a patient hunter, able to search wide areas over long periods with video cameras or infrared seekers, and can also be fitted with radar sensors. Export customers include the former Soviet republic of Azerbaijan, which is fighting a low-level war against neighboring Armenia. Last week the Azeri defense forces reported that they had successfully launched six Harops, hitting targets including a 2S3 self-propelled gun and a bus loaded with Armenian recruits. (There is a video of a Harop taken in the conflict here). The Armenian government has protested against the supply of the drones to their enemies, which suggests they view Harop as a particular threat.

When a nation as unlikely as Azerbaijan is fielding the latest in loitering attack drones, it's easy to see how smaller, cheaper machines like ROTEM could spread. Even if there is no export market, improvised versions may emerge. Small commercial drones have already been pressed into service as battlefield scouts by several factions in Syria. They are used not only by ISIS and by the al-Qaeda-backed Al-Nusra Front but also by their Kurdish opponents.

Consumer drone technology is developing fast as companies like DJI strive to stay ahead with a steady stream of improved models. Like the ROTEM, the new DJI Phantom 4 includes automated collision avoidance for flying in a cluttered environment. The consumer development cycle is very short—the Phantom 1 was launched in 2013, and the new model is twice as fast with greater endurance and far more capable. It is hard to tell who will have the best quadrotors out there in a few years' time.